Databases of reference images and associated identification information can be a useful tool in identification of images captured in the field (e.g. by a law enforcement personnel). However, a database of possible identities may comprise a very large set of images and identification information, making it challenging to utilize such a database in the field. Furthermore, occasions present themselves when it may be necessary to ascertain the identity of an image, e.g., an image associated with a person, during a short encounter. An encounter may last no more than a few minutes and may be shorter. A person who needs to identify the image may have a mobile device with a camera. But it is impractical to store what may be a very large database in a mobile device and challenging to determine the best matches within a short amount of time.